The influence of drugs on aqueous humor formation and drainage in the living monkey eye will be studied, using a variety of perfusion techniques. In some eyes, the ciliary muscle will be surgically disconnected from the scleral spur so that drug effects on the function of the drainage apparatus will not be masked by drug-induced changes in ciliary muscle tone. The morphological basis for any drug-induced functional changes will be studied electron microscopically. These studies may improve our understanding of the pathophysiology and therapy of glaucoma. Cholinesterase inhibitors will be applied topically to the eyes of living monkeys to produce cataracts similar to those caused by the drugs in humans. Surgical and pharmacological manipulations (ciliary muscle disinsertion, ciliary ganglionectomy, ganglionic blockade, cholinergic blockade) will be employed to attempt to inhibit cataractogenicity. These studies may improve our understanding of cataract formation and its inhibition in the human. The in vivo effects of drugs and metabolic alterations on ciliary body vasculature and epithelium will be studied angiographically in surgically aniridic monkeys. These studies may improve our understanding of the pathophysiology and therapy of uveitis, and of the mode of action of antiglaucoma drugs. Active transport of compounds out of the eye by the ciliary body will be studied by perfusion techniques in living surgically aniridic monkeys. These studies may improve our understanding of ocular detoxification mechanisms.